建設機械における軸流冷却ファンの羽根まわりに形成される渦流れ

抄録

The energy loss of the airflow generated by forced convection in the cooling system included in heavy construction machinery is due to friction and turbulence in its ventilation path, and its behavior is three-dimensional. Therefore, computational fluid dynamics (CFD) is effective in clarifying the three-dimensional energy loss mechanism, but there are few reports that three-dimensionally capture the flow field in the cooling system of construction machinery, especially including some components around the axial fan. In this study, the flow field of the entire cooling system was visualized by numerical simulation using ANSYS-CFX17.0, and the effect of the three-dimensional flow field formed around the blades of the axial flow fan on the fan performance was investigated. From the results of CFD analysis, the fan performance is inferior in the case of the axial fan only than in the case of the entire cooling system, which is consistent with the blockage effect of the wing tip leakage vortex limiting the air flowing into the impeller. The wing tip leakage vortex is large-scale and has a high vorticity, and is divided into leading edge of adjacent blade because it flows in the tangential direction while maintaining the same height as the wing tip.